Start-stop electronic regenerative repeater



Feb. 3, 1948. H. F. WILDER 2,435,257

START-STOP ELECTRONIC REGENERATIVE REPEATER Filed Oct. 17, 1942 2 Sheets-Sheet 1 lezq 483 mvzm-oa H. E W LDE R av 77 'NAw TTO EY TO FIG. 2-

Feb. 3, 1948. I v F. WILDER 2,435,257

START-STOP ELECTRONIC REGENERATIVE REPEATER Filed Oct. 17, 1942 2 Sheets-Sheet 2 T0 FIG.I

DELAY NETWORK S CANN|NG IMPULSE I GENERATORS INVENTOR H. F WILD ER Mud Patented Feb. 3, 1948 START- 8 EE'EGTRONIC REGENERATIVE REPEATER' Harold F. Wilder, WyckofiN. J assignor to Thev Western. UnionJI elegraph Company, New York, N. Y.',.a corporation of New York.

Application October-'17, 1942, Serial" No.. 462,368?

20Claims. 1

This invention relates" to; telegraph signal-re.- peaters and has particular reference to-startistop regenerativerepeaters;

An object of they invention is to: provide. an organization of; 'instrumentalities to regenerate telegraph signals in phase which. comprises novel meansincluding a multiz-section delay network.

Another object or the invention is'to provide means for accurately timing the retransmission of. signals which utilizes: a. series oivoltages: derived from successive sections or amulti-s'ection delay network.

Still. another object ot the invention is. to provide apparatus for the regeneration or start-stop signals which utilizes novel. means includin a multiP-section delay network. upon which is; impressed a voltage inresponse to a. start'im-pulse for propagation through the network. and which also employs-voltages derived from successivesec-e tionswof/ the network to time the: retransmission of the intelligence impulses.

A. further object of. the invention is: to: provide means for impressing a voltage on one terminal of. a multi-section delay network in response to the start impulse of a start-stop telegraph signalt and for disabling temporarily said means. to

intelligence impulses. having the same marking or spacing character as: the start impulses.

'I-hese and other objects of. the invention are attained in the illustrative embodiment of theinvention which. willbe described in connection with the accompanying drawings; in which:

Figs. 1- and 2 illustrate a start-stop regenerative repeater in; which: each of a. series of voltages derived from successive sections of a multisection delay network is employed tooperateone of a pair of electron discharge devices individual thereto, by means of which a common pair of electron discharge devices is operated to: generate the timing or scanning impulses.

In its general aspect the invention contemplates the use of a delay network madeup of not less than as many similar sections as: there are impulse units in the signals to be regener ated'. Inthe case of a five unit intelligence code employed in a start-stop signaling system, at least seven suchsections are used, one for each unit. f the intelligence signal plus one each. for the start and rest,- impulses. In response to a. start impulse received at the repeater station, a voltage is impressed upon one.- terminal of the network. This voltage is propagated through the network at a rate determined by the constants of the successive sections comprising 'thenetwork. Preferably, this rate of propaga e tion is such that a. voltage tobeusedfor the generation. of a timing impulse, appears at each section of, the: network at a time; which corre sponds approximately, to'the' middle f a normal signal. Genera-11y; at such a: time, the received signal is an accuratesrcpresentation of thetransmitted: signal. HOWQVGB, ity is considered to be within: the scope;- of' the instant invention to adjust the constants of the;- network' sections so: as to generate; the: timing impulses at anyother time relative; to. the arrival time: of the received signals itit is, found desirable to do so.

The received signals; are also: used to prepare for ope-ratiorrcneorthe other of a pair; of electron discharge devices, depending upon the mark ing or spacing character of the signal. These twotlatter devices are rendered; completely operas tive by the generated timing impulses and control retransmitting means; whereby the signals which are retransmitted; from the repeater station are; complete-lyregenerated-1 both in amplitude and in phase...

Sincev the mean employed for impressinga starting voltage upon" one t -1rmi-nalof the delay network is: continuously in a. position to be influe-need by all of; the received signal impulses, there is: provided an: additional means. responsive tn the voltage'derived' from the last section of the network. for biasing; the voltage impressing means in such'a manner that, after, having initially impressed a starting voltage upon the network, it is disabled; for the period of timev required to retransmit the complete signal. Upon the termination. of the. signal: transmitting period, the voltage impressing means is recondi tioned' to be; responsive to the next "start in pulse whereby a. similar cycle of operation is started.

Rieferringxnow'to; Fig. 1,, the: signals are received from l'imaW byarcceiving relay 68, the contacts which control the. repeater apparatus to. op;- erate. the transmitting relay 69: whereby the Si nals. are repeated into line. E. after; being completely regenerated. Connected? to. the marking contact M and the spacing contact S or the, re.- ceiving relay: 68 are negative and positive bat.- teries: l1: and. H, respectively; whereby, depending upon the position of the armature of this relay, negative and, positive potentials, according. to the marking or spacing characteristics of the received signals, are impressed through a re.- sistance 73. upon a voltage. divider comprising; a series connection of resistances l6, and H... 'ljhe input circuits Of. a minor, pickup. tubes 8,1 and 82 are derived respectively from resistances l6 and TI. The output circuits of the pickup tubes include the two halves of the primary winding of a transformer 83. Space current for the output circuits of the pickup tubes is derived from a series of short unidirectional impulses impressed upon a condenser 85 by means of connections to the secondary winding of a transformer 81. The series of unidirectional scanning or timing impulses is generated under the control of a delay network and apparatus associated therewith in a manner to be described. p

Short impulses of opposite polarity, depending upon the marking or spacing character of the signals impressed upon the input circuits of the pickup tubes SI and 82, are induced in the secondary winding of transformer 83, the terminals of which are connected respectively through resistances SI and 92 to the control grids of a pair of amplifier vacuum tubes 93 and 96, respectively. The cathodes of the amplifier tubes are connected through a common self-biasing resistance 95 to the negative terminal of a source of direct current 90. The output circuits of the amplifier tubes include resistances 99 and NH, which are connected by means of conductors I02, i133 and I04 to the positive terminal of the battery 99.

Since the potentials applied to the input circuits of the amplifier tubes 93 and 94 are of relatively short duration, the tubes are provided with feedback or inverse biasing circuits by means of which their sustained operation in response to the short impulses is secured. These biasing circuits comprise a connection from the anode of one tube to the grid of the other tube. Specifically, the anode of the tube 93 is connected through resistance I05 to the grid of tube 94. Similarly, the anode of tube 94 is connected through resistance I06 to the grid of tube 93.

The operation of the tubes provided with these inverse biasing circuits may be understood by assuming that the tube 93 is conducting and the tube 94 is non-conducting. If in these circumstances an impulse is induced in the secondary winding of the transformer 83 of such a character that the lower terminal of the winding is positive with respect to the upper terminal, the grid of tube 94 will be biased positively with respect to its associated cathode, thereby rendering this tube conducting. The negative potential from the upper terminal of the secondary winding of the transformer 83, which is applied at the same time to the grid of the amplifier tube 93 is efiective to render this tube non-conducting. Consequently, the potential which is applied to the anode of this latter tube is raised to some high positive value approaching the full potential of the battery 96. This high positive potential is impressed by means of the connection including the resistance I05 upon the grid of the amplifier tube 94 which has just been renderedconducting.

These circuits are so designed that positive feedback potential is supplied to the tube last operated before the operating potential derived from the transformer impulse falls to zero. Thus, it is seen that the tube which is non-conducting furnishes a biasing potential to the conducting tube to maintain these conditions. Hence, it become posthe inverse biasing circuits.

The potentials of alternately opposite polarity appearing at the terminals of resistances 99 and I 0| are impressed by means of connections including resistances I01 and I09 upon the respective grids of a pair of power tubes H2 and H3. The cathodes of these tubes are connected through a common self-biasing resistance II4 to the negative terminal of the battery 96. The output circuits connected to the anodes of the power tubes include the oppositely poled operating windings of the transmitting relay 99, the common terminal of which is connected by means of connector I04 to the positive terminal of the battery By reason of this arrangement the amplifier tubes 93 and 94 and the power tubes H2 and H3 follow the operations of the pickup tubes 8! and 82 ina manner depending upon the marking and spacing character of the received signals, whereby the contacts of the transmitting relay 69 are operated to connect to line E negative battery for the transmission of marking signals and positive battery for the transmission of spacing signals.

The armature of the receiving relay 68 is also connected through a resistance H5, a delay network II 6 and a resistance III to the left hand winding of a reading relay II 8. The right hand winding of this relay is connected through a resistance H9 to the armature of the transmitting relay 69. The operation and function of this relay will be described in a later section of the specificatione Also connected to the armature of the receiving relay 68 is a circuit including a condenser I2I in series with a resistance I22 and the parallel connection of the primary winding of a transformer I 23 and a rectifier I24, The secondary winding of the transformer I23 is connected across a con denser I25 included in the output circuit of a pair of latch tubes I26 and I 21. The momentary voltages induced in the secondary winding of the transformer I23 supply anode potentials to the latch tubes through the two halves of the primary winding of a transformer I28. The input circuits of the latch tubes I26 and I21 are connected, in a manner to be described presently, to apparatus associated with one of a plurality of scanning impulse generators. The arrangement is such that the latch tubes are operated alternately for each group of signal impulses received. Consequently, there is induced in the secondary winding of the transformer I29 at the beginning of each signal to be repeated an impulse of short durationand of opposite polarity for each successive signal.

The terminals of the two halves of the sec ondary winding of transformer I28 are connected by conductors I29 and I30, respectively, to'the grids of a pair of network drive tubes I3I and I32. The cathodes of these tubes are connected through a common self-biasing resistance I 33 and over a conductor 434 to the midpoint of the secondary winding of transformer I28 and to the negative terminal of battery 96. Both of these tubes are also provided with inverse biasing circuits whereby they are provided with trigger operating and banking operating characteristics. The output circuits of the network drive tubes include resistances I31 and I38, the common terminals of which are connected by conductors I99 and I40 to the positive terminal of battery 96.

The potentials impressed upon the terminals of the resistances I31 and I38 by the network drive tubes are also impressed through resistances MI and I 42, respectively, upon the grids of a pair of power tubes I43 and M4, respectively. The oathi odes of the power tubesare connected through a common self-biasingresistance I45, conductors 146 and I41 to the negative terminal of the bat-.- tery 9B. The output circuits of the power tubes include resistances I lfl-and I49. the common terminals of which are connected by conductor Hill to a point I5I on a voltagedivider 452 connected across the terminals of the battery 66. This point is positive with respect to the connection made by means of conductors I45 and 141 to the cathodes of the power tubes,

The voltages appearing at the terminals of resistances I48 and I49 are connected to a multisection delay network I53. This network com prises seven similar sections connected in cascade. Only the sixth and seventh sections of the network are shown in complete detail, and each, such as the sixth section, comprises a parallel connection of two inductive elements 54 and I55. Connected between the mi'dpoints of each of the inductances, both halves of each of which are wound on the same core, isa condenser I 56. Also, condensers I51 and 158 are connected between corresponding terminals of the inductances I54 and I55. A potential having a polarity opposite to the previously applied potential is impressed upon the first section of the network 153 substantially at the beginning of the received start impulse, and since it is desired to generate the scanning or timing impulses to coincide with the 'middle of each normal signal, the parameters of the network are adjusted to introduce a delay in the propagation of the applied voltage of approximately half the time required to transmit a full signal impulse. If it is assumed that the rate of signaling is approximately 390 letters per minute, the length of a single signal impulse is approximately 22 milliseconds, and the delay produced by the first network section should be approximately 11 milliseconds. The delay which is introduced by each of the succeeding sections will then be equal to a full signal impulse or 22 milliseconds. The circuit constants for each of the section 2 to 1, inclusive, are therefore such as to produce a delay in the propagation of the impressed voltage of 22 milliseconds per section, in the case where the signaling is efiected at the assumed rate of 390 letters per minute, and the constants of the first sectionof the delay network are such as toproduce a delay of 11 milliseconds. The energy which is transmit-ted through the delay network is dissipated in a terminating resistance comprising-two equal resistances I59 and IBI.

Connections are made from corresponding points on the two parallel conductors of the delay network at the end or" eachsection by means of which voltages are impressed upon the input circuits of a plurality of pairs of vacuum tubes, each of which constitutes a scanning or timing impulse generator. For example, between the fifth and sixth sections of the delay network connections are made through resistances I62 and I63 to the control gridsof tubes I 64 and I 65, respectively. The cathodes of this pair of scanning impulse generators are connected through a resistance I66 and conductor I61 to a point I 68 on the voltage divider I52. These tubes are also provided with inverse 'biasing circuits similar to those previously described. The anodes of the scanning generator tubes I64 and I65 are connected through resistances I12 and I13, respectively, to the terminals of the upper and lower halves of the primary winding of a transformer I14. The midpoint of the transformer primary ill) assassin 6 winding is by means of conductor 4. 40 to the positiveterminal of the battery 96.

The input of of the pairs of scan-- nine impulse generators are connected :9. mannor to that described to individual sectrons of the delay network I53 so that, as the transient voltage progresses through the network, one tube of each of the scanning impulse generators is operated in response to the particular polarity of the transient voltage. The output'cir' oi alternate pairs of the scanning impulse generators are connected to the primary winding "of transtormer 4 as described. The output circuits of the other scanning impulse generators are connected to the primary Winding of transformer H4 in a reverse manner. For example, the output circuits of the tubes I15 and "I16 are connected respectively through resistances I11 and I18 to the terminals of the lower and upper halves or the primary winding of transformer 114 in contrast to the connections of the output circuits of the preceding tubes I64 and IE5 and also the succeeding tubes I19 and I8 I.

Since, during a given cycle or operation, points on the upper conductor of. the delay network 153 are of a positive polarity with respect to corresponding point on the lower conductor of the network, the upper tube of each of the pairs of scanning impulse generators will be rendered con ductingo By reason oi the alternate reverse connection of the output circuits of these tubes, there are generated in the secondary winding of the transformer I14 impulses of alternating polarity. The midpoint-ofthe secondary winding is connected by means of conductor I41 to the negative terminal of battery 96. The cathodes of tubes [84 and I85 are connected to a point I86 on the voltage divider I52. Since this point is positive with respect to the negative terminal of the battery 96 which is connected over conductor I41 and the two halves of the secondary winding oi transformer I14 to the control grids of the tubes I84 and N5, the input circuits of'these tubes are biased normally below the cut-off potential. Thus, the impulses of alternate polarity which are derived from the secondary winding of transformer I14 serve ascontrol potentials for the input circuits of tubes I84 and I85, whereby these tubes are conditioned for alternate operation for short periods or time.

The anodes'of the tubes I84 and I85 are con nected respectively to the'upper and lower halves of the primary winding of transformer 81. The common terminals of the two halves of the primary winding are connected to the positive terminal of battery 96, which supplies space current to the tubes I84 and I85 through the primary winding of the transformer. The connections between the anodes of the tubes and the trans former primary winding are such that unidirectional impulses of short duration are induced in the secondary windingof the transformer 81 irrep sms of whic i lb n r z h ary winding. Thuathe tube s I84 and I 85 together with the tran's'iormer 31 constitute a rectifier. As previously described, the series of'unidirectional impulses induced in the secondary winding of the transiormersupplies space current at accurate periodic intervals to the pickup tubes BI and 82 whereby phase distortion in the received signals is corrected before the signals are retransmitted.

Connections are made from the anodes of the scanning impulse generator tubes I19 and I81 through the respective resistances I81, I88' and conductors I89, I9I to the control grids of the respective latch tubes I21 and I26. These connections are for the purpose of conditioning for operation one of the latch tubes as soon as a signal has been repeated so that the conditioned tube may respond to the sta impulse of the following received signal. .Since'the polarity of the potential applied to the input circuits of the latch tubes is not changed until a transient voltage, which is applied to the delay network under the control of the operatively conditioned latch tube in response to a start impulse, has completely traversed the network to operate one of the tubes H9 or I8I of the seventh scanning impulse generator, any intelligence signal impulses of a spacing character will not reverse the polarity of the potential induced in the secondary winding of transformer I28 from that resulting from the reception of the start. impulse.

The following portion of the specification describes in sequence the operation of the various elements comprising the repeater in repeating a group of marking and spacing impulses constituting a start-stop signal. For the purposes of the description, assume that when no signals are being transmitted marking potentials are applied to the lines W and E and that steady state conditions exist at the repeater. The armature of the receiving relay 68 is engaged with itsmarking contact M to apply negative battery tothe various circuits connected thereto. This negative battery conditions the input circuit of the pickup tube 82 for operation. The amplifier tube 94 is banked in a conducting condition, and amplifier tube 93 is non-conducting, thereby rendering the power tube IIZconducting and the power tube Shun-conducting. Current flows from the positive terminal of. the battery 98 through the upper winding of the transmitting relay 69 in a direction to operatethe armature of this relay to its marking contact M and thereby connect negative battery to line E. The input circuit of the latch tube I26 is conditioned for operation by reason of the positive potential appearing on conductor I9I The network drive tube I 3| is assumed to be banked in a conducting condition, and drive tube I32 is non-conducting, thereby effecting the operation of power tube I 44 and the non-operation of power tube I43. This condition applies a voltage upon the input terminals of the delay network I53 in such a manner that all points on the upperconductor thereof are of a positive polaritywith respect to corresponding points on the lower conductor. Consequently, the upper, tubes such as I64, I15 and I19 of the seven pairs of scanning impulse generators are banked in conducting conditions. All of the lower tubes such as I65, I16 and I8I of the scanning impulse generators are non-conducting. Consequently, the anode of tube I8! is more positive than the anode of tube I'I9 whereby conductor I9I is positive with respect to conductor I89. The effect of this condition is that the grid of the latch'tube I26 is positive with respect to its associated cathode, and the grid of the latch tube I27 is negative. with respect to its associated cathode. Neither of the rectifier tubes I84 or I85 is conditioned for operation at this time because of thenegative bias which is applied to the respective grids by means of the previously described connection to the voltage divider I52.

In response to the spacing signal representing a start impulse, the armature of the receiving relay 68 is moved to its spacing contact, S, thereby applying positive battery to the circuits connected thereto. Pickup tube 8! is conditioned for operation, and pickup tube 82 is biased to cut oil. The condenser I2I is charged to a positive potential through the primary winding of transformer I23. The impulse which is induced in the secondary winding of this transformer by the surge of charging current through the primary winding causes the momentary conduction of space current in the latch tube I26 through the upper half of the primary winding of transformer I28. A voltage is induced in the secondary winding of this transformer of such a polarity that the network drive tube I32 is rendered conducting and the drive tube I3I is rendered non-conducting. Resulting from this operation, conduction of space current is started in the power tube I43 and is discontinued in the power tube I44 whereby the polarity of the voltage which is impressed upon the input terminals of the delay network I53 is reversed fom that previously existing.

As this voltage is propagated through the successive sections of the delay network, the conductors thereof are conditioned in such a manner that points-on the upper conductor are negative with respect to corresponding points on the lower conductor. Consequently, the scanning impulse generator tubes controlled by voltages appearing at these spaced points are operated successively to interrupt the flow of space current in the upper tubes such as I64, I15 and I19 and to initiate the conduction of space current in the lower tubes such as I65, I16 and NH. With the operation of each pair of scanning impulse generator tubes, impulses of short duration and alternating in polarity are induced in the secondary winding of transformer I'M. These impulses are rectified by means of the tubes I84 and I85 and the transformer 81, inducing in the secondary winding of the transformer a series of short unidirectional impulses. As previously described, these impulses serve to operate the amplifier and power tubes 93, 94 and H2, H3, re-

spectively, in a manner determined by the marking or spacing character of the signal impulses whereby either the upper or the lower winding of the transmitting relay 69 is energized to retransmit the signals into line E. Specifically, in the case of the spacing impulse representing the start impulse, amplifier tube as is rendered conducting, and amplifier tube 94 is rendered non-conducting, and power tube H2 is rendered non-conducting and power tube H3 is rendered conducting. Current is thus caused to flow through the lower winding of transmitting relay 69 in a direction to move the armature thereof into engagement with is spacing contact S whereby positive battery is connected to line E to retransmit the spacing "start impulse.

Succeeding impulses of the signal cause the operation of the repeater apparatus in a manner which should be obvious in view of the foregoing description. Finally, the marking rest impulse is received and retransmitted in the manner described, after which the apparatus is left in the condition assumed at the outset of this description, with the exception that the latch tube I 21 is now conditioned for operation, the

network drive tube I32 and the power tube I 43 are in conducting conditions, and also the lower tubes of the scanning impulse generators are now conducting.

It has been found in practice that there is en countered occasionally a condition which would .result in the operation of the transmitting relay caged with its spacing contact S during periods of no signal transmission if precautions were not taken to prevent such an occurrence. Such a condition would occur during an idle period by the establishmentof a spacing signaling condition on the line W which positions the armature of the receiving relay 68 on its spacing contact S. As described, such an operation reverses the polarity applied to the delay network I53 whereby subsequently a series of scanning impulses are generated; Also, the pickup tube BI is operated by each scanning impulse and effects the operation of amplifier tube 93 and power tube H3 whereby the lower winding of the transmitting relay 69 is energized to connect positive spacing battery to line E through the armature and spacing contact S of the relay. If the spacing line condition lasts for a time longer than that required to transmit a start-stop signal, the delay network I53 would be in a steady state condition so that no further scanning impulses are generated. If now a marking signaling condition be applied to the line W, the armature of relay 68 would move to its marking contact M and thereby condition the pickup tube 82 in preparation for the repetition of a marking signal into line E. However, the connection of the negative battery H to the charging circuit of the condenser I2I results in a current flow through the rectifier IZG, thereby by-passing the primary winding of transformer I23. Consequently; there is not generated in the secondary winding of transformer I28 an impulse necessary for the reversal of polarity on the delay network I53. Hence, there is not generated a scanning impulse under the control of the delay network I53 whereb the pickup tube 82 may be completely conditioned for operation to relay the marking condition to the transmitting relay 69 and thereby apply negative marking battery to line E. Thus, it is seen that the receiving relay 68 would be left in its normal marking rest condition, and the amplifier tube 93, the power tube I I3 and the trans.- mitting relay 69 would be left in abnormal spac ing conditions whereby positive spacing battery would be applied to line E. Such a condition is undesirable for the reason that the effect is to leave the line E in a spacing or open condition so that any start-stop apparatus responsive to signals received over this line would be kept continuously cycling, since the steady spacing con dition has the efiect of a start signal on such apparatus. Such a line condition could exist, if steps were not. taken to prevent its occurrence, until start-stop signals were again received from the line W, and in this case the first of such signals in all probability would be mutilated because of an asynchronous relation between the signals andthe start-stop printing apparatus connected tolineE.

Relay H8 serves to prevent the occurrenceof the described possible line condition. This may be seen by considering the receiving relay 68' as positioned on its marking contact M and the transmitting relay 69 as ositioned on its s acing contact S. In this case negative battery is connected through the marking contact M of receiving relay t8 and the delay network lid to the left hand winding of relay H8. The right hand winding of this relay is connected through resistance Hg and the spacingcontact S of the transmitting relay 69 to positive battery. The relay is diiferentially wound so that under the described conditions'the fluxes generated by the two windings are additive and cause the closure of the make contact. This operation results in the connection of the positive terminal of bat tery 98 over conductors ms and I03, the make contact of relay H8 and resistance I93 to the grid of the amplifier tube 94. This tube is, there fore, operated, and the amplifier tube 93 is rem derednon-conducting. Consequently, the power tube H2 is operated, and the power tube H3 is rendered non-conducti'ng to energize the upper winding of the transmitting relay .69 wheieby the armature thereof is moved into engagement with its marking contact M. Thus, the desired marking rest condition is applied to the line It will be seen that the relay H8 is not .operated during the repetition of normal start-stop signals vfor the reason that the half-signal delay normally occurringv between corresponding op erations of the receiving relay 68 and the trans mitting relay 69 iscompensated for by the de-; lay network I I6. The parameters of this network are adjusted to introduce a delay of ILmillie seconds in the impression of thepotentials of batteries 'II and I2 upon the left hand winding of relay IIB. Thus, by the time that the receiving relay contact potentials are applied tothe left hand winding of the relay, similar potentials are applied to the right hand winding thereof from the contacts of the transmitting relay. The polarity of these potentials will agree at all times so that the fluxes generatedin the two relay windings willbe in opposition, thereby preventing the closure of the relay contacts. 4

While the power supply for the various elec tronic elements of the repeater is shown as asingle battery 96, it is contemplated to be within the scope of the invention to provide individual batteries, if desired; Also, the potentiometer I 52 may include the heater elements ofthe tubes in any well-known arrangement whereby the desiredpo; tentials may be secured for tube biasing, and so forth.

The nature of the invention may be ascertained from the foregoing description of an illustrative embodiment, it being understood thatchan'ges in the invention herein disclosed may be madewithin the scope of what is claimed without departing from the spiritof the invention.

What is claimed is: v

l. A regenerative telegraph repeater comprising a signal receiving device, a signal transmit ting device, means prepared for operation by said signal receiving device in accordance with the character of the received signals and operable to control. said signal ,transmittingdevice, adelay network having a plurality of sections connected in cascade, means controlled by said receiving de vice for impressing a voltage on one terminal of said network preceding the receipt of a group of intelligence signals, and means controlled by voltages derived from succeeding sections of said net work for timing in a predetermined manner the operation of said transmitting device control means.

2 A regenerative repeater for sitart stop tele graph signals comprising a signal receiving de vice, a signal transmitting device, means for controlling the operation of said signal transmitting device in accordance with the, character of said received signals, said controlling means being partially operatively conditioned by said signal receiving means; a delay network havinga caded connection of a plurality of sections; means controlled b said signal receiving means re sponse' to a start signal to impress a voltage 11 upon one terminal of said delay network for propagation through successive sections thereof, and means utilizing the transient voltages appearing in successive sections of said network for completing the operative conditioning of said transmitting device control means at predetermined time intervals. 7

3. A regenerative repeater for start-stop telegraph signals comprising a relay for receiving signals from an incoming line, a second relay for transmitting signals to an outgoing line, electronic means prepared for operation by said receiving relayinaccordancewiththecharacterofsaidreceived signals and operable to control the operation of said transmitting relay correspondingly, a delay network comprising a cascaded connection of a plurality of reactive sections, means controlled by said receiving relay in response to a start signal for impressing a voltage upon the first of said sections for propagation through successive sections of said network, and means including connections from successive sections of said network for timing the operation of said electronic means in a predetermined manner.

4. A regenerative repeater for start-stop telegraph signals comprising a relay for receiving signals from an incoming line, a second relay for retransmitting regenerated signals to an outgoing line, a pair of electronic devices arranged to be prepared for alternate operation by said receiving relay in accordance with the character of said received signals and operable to control the operation of said transmitting relay correspondingly, a delay network comprising a cascaded connection of a plurality of sections each including a series inductance and a parallel capacity, a pair of electronic devices controlled by said receiving relay in response to a start signal to impress a voltage upon the first of said sections, and means utilizing the transient voltages propagated through successive sections of said network for timing in a predetermined manner the operation of said first named pair or electronic devices.

5. In a regenerative repeater for start-stop telegraph signals, a signal receiving device, a signal transmitting device, a delay network comprising a plurality of reactive sections corresponding in number to the impulse units in the signals to be retransmitted for timing the operation of said transmitting device to regenerate the signal re ceived by said receiving device, means responding to a start signal and tending to respond to succeeding intelligence signals of a, like character for impressing a voltage upon one terminal of said network, and means responsive to a voltage derived from the other terminal of said network for rendering said first named means responsive only to the following start signal.

7 6. In a regenerative repeater for telegraph signals of marking and spacing characteristics according to a prearranged code, a signal transmitting device, a delay network comprising a, cascaded connection of a plurality of reactive sections, means for impressing a voltage upon one terminal of said network for propagation through successive sections thereof at a rate determined by the electrical constants of said sections, means prepared for operation by and in accordance with the marking or spacing character of telegraph signals, a pair of electronic trigger devices to operate said transmitting device, means utilizing the transient voltages derived from successive sections of said network for generating a series of unidirectional impulses, and means utilizing said series of impulses to operate said sig-'- nal prepared means whereby one or the other of said trigger devices is operated depending upon the marking or spacing character of the signal. a

7. The invention as defined in claim 6 further characterized in that said impulse generating means includes a pair of electronic trigger devices having the input circuits thereof comiected to the junction points of successive sections of said network.

8. The invention as defined in claim 6 further characterized in that the impulse generating means includes a pair of gaseous arc conduction tubes having the control grids thereof connected to alternate junction points of the sections of said delay network.

9. The invention as defined inclaim 6 further characterized in that the impulse generating means includes a plurality of pairs of electronic trigger devices, one pair for each of the sections of said network, and each pair having its input circuits connected to the junction point between two successive sections of said delay network.

10. In a regenerative repeater for the retransmission of received telegraph signals, a repeating device, means for preparing said device for operation in accordance with the marking and spacing character of the received signals, and means including a delay network comprising a plurality of reactive sections corresponding in number to the impulse units in the signals to be retransmitted for accurately timing in a predemined manner the operation of said repeating device.

11. In a regenerative repeater for the retransmission of received telegraph signals, a repeating device having input and output circuits, means for conditioning the input circuit of said device in accordance with the marking or spacing character of the received signals, and means including a delay network comprising a plurality of reactive sections corresponding in number to the impulse units in the signals to be retransmitted for operatively conditioning the output circuit of said device at predetermined accurately timed intervals whereby said signals are retransmitted free from amplitude and phase distortion,

12. In a regenerative repeater for the retransmission of received telegraph signals, repeating apparatus including a pair of electronic devices each having input and output circuits, means controlled by the received signals for conditioning the respective input circuits of said electronic devices in accordance with the marking or spacing character of the received signals, a delay network comprising a cascaded connection of a pinrality of reactive sections, and means controlled by voltagesderived from succeeding sections of said network to furnish space current for the output circuit of the operatively conditioned one of said electronic devices whereby the signals are retransmitted at accurately timed intervals.

13. In a regenerative repeater for the retransmissionof received telegraph signals, a repeating device, means controlled by said received signals for preparing said device for operation in accordance with the marking or spacing charactor of the received signals, a delay network comprising a cascaded connection of a plurality of reactive sections, means for impressing 3, voltage upon one terminal of said network in advance of the receipt of the intelligence signals, and means controlled by voltages derived from succeeding sections of said network for accurately timing in a predetermined manner the operation of said repeating device.

14. In a telegraph repeater, a signal receiving device, a signal transmitting device, means controlled by said receiving device for correspondingly operating said transmitting device, means for delaying the response of said transmitting device to the operations of said receiving device for a predetermined time, and means jointly controlled by said receiving device and said transmitting device for insuring the operation of said transmitting device in correspondence with the operation of said receiving device.

15. In a telegraph repeater, a receiving relay associated with an incoming line, a transmitting relay associated with an outgoing line, means controlled by the contacts of said receiving relay for correspondingly operating the contacts of said transmitting relay after the lapse of a predetermined time interval, an auxiliary relay controlled jointly by the contacts of said receiving relay and the contacts of said transmitting relay, means including contacts of said auxiliary relay when operated to condition said transmitting relay for the impression upon the outgoing line of a marking signaling condition, and a delay network included in the connection of the contacts of said receiving relay to the auxiliar relay to delay the control of said auixiliary relay eiiected by the receiving relay for the predetermined time necessary for the corresponding operation of the contacts of the transmitting relay whereby a conformity in the operations of the receiving and transmitting relays is ineffective to operate the auxiliary relay.

16. A regenerative telegraph repeater comprising a signal receiving device, a signal transmitting device, means prepared for operation by said signal receiving device in accordance with the character of the received signals and operable to control said signal transmitting device, a delay network having a plurality of sections connected in cascade, means controlled by said receiving device for impressing a voltage upon the first of said sections preceding the receipt of a group of intelligence signals, and means controlled by voltages derived from succeeding sections of said network for timing in a predetermined manner the operation of said transmitting device control means, the constants in said first section causing the section to introduce a delay in the propagation of the applied voltage of approximately half the time required to transmit a full signal, thereby to generate the timing impulses to coincide with the middle of each normal signal.

17. In a telegraph signal repeater, a signal responsive relay, a normally inactive impulse generator, means controlled by said relay for setting said generator in operation upon the reception of a start signal impulse by the relay, a sig-- nal transmitting relay, means controlled jointly by said signal responsive relay and said impulse generator for operating said transmitting relay, a plurality of electron discharge devices operable successively by said impulse generator and means controlled by the last operated one of said electron discharge devices for causing said impulse generator to restart its pulsing cycle upon the reception of the next start signal impulse by said signal responsive relay.

18. In a telegraph signal repeater, a signal responsive relay, a normally inactive impulse generator, means controlled by said relay for setting said generator in operation upon the reception of a start signal impulse by the relay. a signal transmitting relay, mean controlled jointly by said signal responsive relay and said impulse generator for operating said transmitting relay, a series of electron discharge devices operable successively by said impulse generator and means controlled by the last electron discharge device in said series for causing said impulse generator to restart its pulsing cycle upon the reception of the next start signal impulse by said signal responsive relay.

19. In a regenerative repeater for start-stop telegraph signals, a signal receiving device, a signal transmitting device, a timing network comprising a plurality of timing sections corresponding in number to the impulse units in the signals to be retransmitted for timing the operation of said repeater in cycles corresponding to the intervals of start-stop telegraph signal combinations, means responsive to a start signal for impressing a voltage upon one terminal of said network, and means responsive to a voltage derived from the other terminal of said network for rendering said first named means responsive only to the following start signal.

20. In a regenerative repeater for the retransmission of received telegraph signals, a repeating device, means for preparing said device for operation in accordance with the marking and spacing character of received signals, and means including a timing network comprising a plurality of timing sections corresponding in number to the impulse units in the signals to be retransmitted for timing the operation of said repeating device in cycle corresponding to the intervals of telegraph signal combinations.

HAROLD F. WILDER.

REFERENCES CITED UNITED STATES PATENTS Name Date Kinkead Oct. 18, 1938 Number 

